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  • Smart Learning for All

  • Topic: Pneumonia.

  • What causes pneumonia?

  • The letter P. No.

  • Pneumonia is a lung infection caused by microorganisms which generally leads to difficulty in breathing.

  • Normally, we inhale oxygen rich air which reaches our alveoli.

  • Alveoli are surrounded by blood capillaries.

  • Here, the oxygen through the walls of alveoli diffuses into our blood.

  • However, sometimes we also inhale harmful microorganisms.

  • Mostly, the cilia and mucous in our respiratory tract trap these microorganisms, which are then expelled while coughing.

  • But sometimes the microorganisms don't get trapped and reach the alveoli.

  • There they start to multiply, causing lung infection, that is, pneumonia.

  • No.

  • Now what to do?

  • Now, to protect ourselves, the immune cells start attacking the microorganisms, causing inflammation and accumulation of fluid in the alveoli.

  • As a result, the inhaled oxygen cannot get easily diffused into blood, thus causing difficulty in breathing.

  • Topic: Dandruff.

  • Why do we get dandruff?

  • Tearing of pages.

  • No.

  • Dandruff is a condition in which our scalp sheds skin cells in the form of white flakes.

  • A yeast called Malassezia globosa, is one of the mostly accepted reasons for causing dandruff.

  • Wow.

  • What a classy name it has.

  • Indeed.

  • Malassezia globosa is naturally present on our scalp.

  • It feeds on sebum and releases oleic acid.

  • Now, some people are sensitive to this oleic acid.

  • When it penetrates the upper layers of their skin, it causes inflammation.

  • Hence, in response to this inflammation, their skin sheds a large number of skin cells at a higher rate.

  • These cells then join together forming white flakes, thus causing dandruff.

  • Topic: Joints.

  • Why do knuckles pop?

  • So that when we get bored we can pop them for time pass.

  • No.

  • A knuckle is a joint in the finger where two bones come together or connect.

  • This joint is filled with a fluid called synovial fluid.

  • Synovial fluid is a viscous fluid containing dissolved gases like oxygen and carbon dioxide.

  • When bones move, the synovial fluid prevents them from grinding against each other.

  • Wow.

  • It is so amazing.

  • Indeed.

  • When we stretch or bend our finger, the space between the two bones increases.

  • This causes the synovial fluid to stretch, thus creating low pressure in it.

  • Now, as gases are less soluble at low pressure, the dissolved gases in the synovial fluid undissolve, resulting in the formation of a bubble, which we hear as the pop sound.

  • Topic: Anaerobic respiration.

  • What is the cause of muscle cramps?

  • Excess sleep.

  • No.

  • Respiration is a process in which the cells of our body produce energy.

  • Normally, our cells respire aerobically.

  • In this process, the glucose with the help of oxygen is completely broken down to produce energy, water and carbon dioxide.

  • Is this energy then used for all our activities?

  • Indeed.

  • However, during heavy exercise, our body cannot deliver enough oxygen to the cells of our muscles.

  • Hence, in such situations anaerobic respiration helps us to produce some energy temporarily and thus, continue our work.

  • In anaerobic respiration, the glucose is partially broken down in the absence of oxygen to produce comparatively less amount of energy and a waste product called lactic acid.

  • Now, one of the most prominent reasons for the muscle cramps is the accumulation of this lactic acid.

  • Topic: Sinkholes.

  • What causes sinkholes?

  • Maybe water.

  • This time you are absolutely correct.

  • Yes.

  • A sinkhole is a depression or cavity in the ground which is caused by water erosion.

  • Water erosion is a naturally occurring process in which water wears off soil and rocks.

  • Wow.

  • Water is so powerful.

  • Indeed.

  • Now listen.

  • The upper layers of the soil comprise of sand, clay, etc.

  • While the bottommost layer called bedrock has rocks.

  • Generally, sinkholes form in places where the bedrock layer has rocks made up of limestone or dolomite.

  • When rain falls, it seeps into the soil reaching the bedrock.

  • Over time, the water dissolves these rocks and thus, erodes them forming hollow cavities.

  • As these cavities get bigger, the ceiling of the cavity, that is, the upper layers of soil cannot hold the weight, hence they collapse forming sinkholes.

  • Topic: Human Nose.

  • Why do we get nosebleeds?

  • I don't know.

  • Alright.

  • I will explain.

  • The medical term for a nosebleed is epistaxis.

  • The most common epistaxis is anterior epistaxis where bleeding happens from the front part of our nostrils.

  • Each of our nostrils has a mass of blood vessels called Kiesselbach's plexus which is very close to the skin surface.

  • Now, usually the mucus moisturizes the skin in our nose, thus protecting the blood vessels in it.

  • Wow.

  • Mucus is so useful.

  • Yes.

  • It is.

  • However during winter, the air is dry.

  • Hence, when we inhale this dry air, it draws moisture from the mucus which in turn leads to the drying of skin in our nose.

  • Now, some people's skin is very sensitive.

  • If it dries, the skin and blood vessels in it get easily damaged causing an anterior epistaxis or nosebleed.

  • Topic: Vaccines.

  • How do vaccines work?

  • By giving extreme pain.

  • Not at all.

  • Vaccines train our body to fight against the dangerous disease causing pathogens.

  • Oh really.

  • Do they have a training academy?

  • You are just unbelievable.

  • Vaccines often contain weakened or dead pathogens.

  • When they are injected into our body, they just trigger the immune response but do not cause fully fledged diseases.

  • Our immune cells recognize these pathogens as foreign invaders and thus, produce antibodies.

  • These antibodies kill the pathogens.

  • Also, the immune cells record the information about the pathogens and the way they were killed.

  • Hence, in case in the future, a similar strong pathogen enters our body, our immune cells remember and easily identify that pathogen.

  • They produce the required antibodies to fight it back.

  • Thus, we remain healthy.

  • Topic: Cheese.

  • Why does Swiss cheese have holes?

  • Those are not holes.

  • They are eyes of the cheese.

  • No.

  • Cheese is made from milk.

  • Milk contains a sugar called lactose which is very important in the formation of cheese.

  • Now while making Swiss cheese, bacteria like S. Thermophilus, Lactobacillus and P. Shermani are added to milk.

  • What?

  • Bacteria are added to milk?

  • Absolutely.

  • However, they are good bacteria.

  • Out of these bacteria, the S. Thermophilus and Lactobacillus first convert the lactose into lactic acid, producing curd.

  • Then after undergoing certain processes, when the curd is kept for maturing, the P. Shermani bacteria consumes the lactic acid and releases carbon dioxide gas.

  • Being trapped, the carbon dioxide gas forms bubbles.

  • Eventually, when we cut the cheese, the bubbles pop, resulting in holes in the Swiss cheese.

  • Topic: Chapped lips.

  • What causes chapped lips?

  • Making weird faces.

  • No.

  • Our lips are very sensitive.

  • This is because the outermost layer of our skin called stratum corneum is much thinner on our lips than on any other body parts.

  • As it is thinner, the blood vessels inside them are more prominent making our lips appear reddish or pinkish.

  • Besides this, the skin on our lips doesn't have oil and sweat glands which secrete substances to moisturize the lips.

  • Hence, our lips have very less moisture.

  • Now, usually during cold months, as the air has less moisture, the moisture from our lips evaporates causing them to get dry and chapped.

  • So to provide moisture, we can lick our lips and apply saliva.

  • No.

  • Saliva draws more moisture and heat from our lips and evaporates, thus leaving our lips more drier than before and thus, making the condition worse.

  • Topic: Pins and needles.

  • Why do limbs fall asleep?

  • Because they are tired.

  • No.

  • It basically happens because of nerves.

  • Through nerves, our brain communicates with our limbs.

  • Nerves are so amazing.

  • Yes.

  • However, when we cross our legs or sleep on an arm for very long, we apply pressure causing the nerve pathways and its surrounding arteries to squeeze.

  • Hence, the nerves do not work properly and the arteries cannot supply required nutrients to the nerves.

  • As a result, the signals sent by our brain do not reach the limb.

  • Thus, we cannot move it.

  • So, we say that our limb has fallen asleep.

  • Also, in some situations, some of these squeezed nerves stop sending signals while some fire hyperactively.

  • This gives us the sensation of pins and needles.

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